The following abbreviations are herewith defined:
3GPP third generation partnership project
FDMA frequency division multiple access
HSUPA high speed uplink packet access
IEEE institute of electrical and electronics engineers
IP internet protocol
L2 layer 2 (medium access control, MAC)
LCID logical channel identifier
LTE long term evolution
MAC medium access control (layer 2, L2)
Node B base station
NRT non-real time
PDU protocol data unit
PHY physical layer (layer 1, L1)
PS packet scheduler
QoS quality of service
RLL radio link layer
RLSP radio link service profile
RNL radio network layer
RRC radio resource control
RT real time
UE user equipment
UL uplink (UE to Node B)
UMTS universal mobile telecommunication system
UTRAN UMTS terrestrial radio access network
VoIP voice over internet protocol
WiMAX worldwide interoperability for microwave access (IEEE 802.16 standard)
An aspect of the long term evolution (LTE) of UTRAN, which may at times be referred to as 3.9G, relates to UE buffer reporting schemes to support uplink (UL) packet scheduling, that is, the process of allocating radio resources for the transmission of data from the UE to the Node-B.
In the UL, a cell specific PS does not have immediate access to the transmission buffers. However, without a priori knowledge of the data available for transmission in the UE buffers, the uplink Node-B PS can only schedule users blindly (or based on the level of utilization of the previously allocated resources). This is clearly not an optimal solution, as it can be wasteful of system bandwidth and other finite resources.
It can be noted that a priori knowledge of the data available for transmission in the UE buffers is particularly important with orthogonal multiple access technologies such as single carrier FDMA, which has already been specified for use in 3GPP for the UTRAN LTE uplink.
Different buffer reporting schemes to support fast uplink packet scheduling have been defined in previous communication standards such as IEEE 802.16 (WiMax) and the UMTS uplink evolution (HSUPA).
In WiMax, a variety of buffer reporting schemes have been standardized, each one optimized for a particular data application. The buffer reporting schemes defined for HSUPA include the so-called happy bit, and the reporting of more specific buffer information (scheduling information). However, neither of these approaches is optimally suited for use in UTRAN LTE to enable efficient QoS-aware packet scheduling, while also providing reduced signaling overhead.